库未加载：尝试使用 mysql2 gem 在 OS X 10.6 上运行“rails server”时出现 libmysqlclient.16.dylib 错误

我已经为此苦苦挣扎了一段时间。

我已经在我的 Snow Leopard 机器上安装了 Rails 3、gem、mysql。一切都很顺利，直到我创建了我的第一个项目并尝试运行

rails server

运行后我得到：

jontybrook$ rails server
/Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle: dlopen(/Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle, 9): Library not loaded: libmysqlclient.16.dylib (LoadError)
  Referenced from: /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle
  Reason: image not found - /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle
    from /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2.rb:7
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:64:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:64:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:62:in `each'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:62:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:51:in `each'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:51:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler.rb:112:in `require'
    from /Users/jontybrook/Dropbox/CODING/simple_cms/config/application.rb:7
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.3/lib/rails/commands.rb:28:in `require'
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.3/lib/rails/commands.rb:28
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.3/lib/rails/commands.rb:27:in `tap'
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.3/lib/rails/commands.rb:27
    from script/rails:6:in `require'
    from script/rails:6
jontybrook$ 

据我所知，问题出在 mysql2 gem 上。 MySQL 似乎运行良好，我的 Gemfile 引用了 mysql2，我的 database.yml 文件似乎也正常。

错误提到

Reason: image not found - /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle

And yet

jontybrook$ cd /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2
jontybrook$ ls
client.rb   em.rb       error.rb      mysql2.bundle result.rb

MySQL2.bundle有吗！？

如果我使用旧的 mysql gem，WEBrick 启动正常。但这并不理想，不是吗？

我已经尝试了谷歌可以给我的一切！非常感谢任何帮助。

我从来没有能够得到任何对我有用的答案，但这是我用来让它为我工作的命令。这样你就不需要每次更新mysql时都使用install_name_tool

sudo ln -s /usr/local/mysql/lib/libmysqlclient.18.dylib /usr/lib/libmysqlclient.18.dylib